The Ulster Unionists have warned the DUP against blocking a ban on MLAs taking council seats.
Legislation tabled by independent unionist Dawn Purvis on double-jobbing is at an advanced stage at the Assembly.
But Ms Purvis is predicting that the DUP will use a veto mechanism to kill the Bill.
Ulster Unionist MLA Danny Kinahan said: “Since Dawn Purvis introduced her private members' Bill, we have been in full support.
“We continue to believe that a politician should have one elected position and one elected position only. If speculation that the DUP may try to scupper her Bill at the final stage for narrow political gain is true, this is a sad reflection of a party willing to take the electorate for granted.”
The legislation aims to prevent MLAs simultaneously holding councillor posts.
Double-jobbing also continues between Westminster and Stormont, with nine of Northern Ireland's 18 MPs also having Assembly seats.